Measuring apparatus and instruments used for displaying a machine's operating condition; electric and electronic actuators and sensors, namely, inductive, capacitive and magnetic proximity sensors, opto-electronic sensors, laser sensors, photoelectric sensors, object detection systems, namely, contour and positive verification sensors, color detection sensors; identification systems, namely, data matrix code readers; inductive sensors for valves, sensors for pneumatic cylinders, incremental and absolute encoders, rotary encoders, speed sensing switches, standstill monitors, slip monitors, synchronization monitors; fluid sensors, namely, flow sensors and switches, flow rate meters, level sensors, pressure sensors, and temperature sensors; sound measuring equipment and oscillation measuring equipment, namely, sound wave sensors for vibration analysis of plant equipment; electronic signal emitters; electronic components for bus systems, namely, masters, power supplies, I/O modules; evaluation systems, namely, programmable counters, direction monitors, multi-function displays, frequency-to-current converters, and power supplies; connectors and splitter boxes; electric and electronic visual display apparatus used for displaying machine operating conditions